The FK506-binding immunophilin FKBP51 is transcriptionally regulated by progestin and attenuates progestin responsiveness
The FK506-binding immunophilin FKBP51 is transcriptionally regulated by progestin and attenuates progestin responsiveness
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DOI：
10.1210/en.2003-0092
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发表时间：
2003-06-01
期刊：
影响因子：
4.8
通讯作者：
Scammell, JG
中科院分区：
文献类型：
--
作者：
Hubler, TR;Denny, WB;Scammell, JG
FKBP51和FKBP52是大分子量的FK506结合亲免素，具有多种生化功能。研究最多的是它们作为类固醇激素受体成分所发挥的作用。差异显示和基因阵列筛选已将 FKBP51 鉴定为孕激素诱导基因。在这里，我们证明了孕激素对 T-47D 细胞中 FKBP51 mRNA 和蛋白质的增强作用。 20 nm R5020 使 FKBP51 mRNA 和蛋白质水平增加 3 倍。 FKBP51 mRNA 的诱导不受 1 mug/ml 放线菌酮的影响，但被孕激素受体 (PR) 拮抗剂 RU486 (1 muM) 阻断。含有人 FKBP51 蛋白基因 (FKBP5) 5' 侧翼序列 3.4 kb 和 427 bp 的报告质粒在 T-47D 细胞中表现出孕激素的调节作用。含有 19 bp 上游序列的构建体表现出基础活性降低且不受 R5020 刺激。为了测试升高的 FKBP51 是否影响孕激素反应性，用人 FEBP51、PR 和小鼠乳腺肿瘤病毒荧光素酶质粒转染 HepG2 细胞，并用 R5020 (0.03-10 nm) 处理。 FKBP51 的表达使 PR 反式激活的 EC50 增加了 3.2 倍。松鼠猴（一种具有天然孕激素抗性的新世界灵长类动物）的 FKBP51 表达更显着地增加了 EC50（与对照相比，11.7 倍）。四三肽重复结构域中带有双点突变的FKBP51的表达对PR反式激活没有影响。这些结果表明，孕激素增加 FKBP51 的表达可能会减弱激素调节细胞中孕激素的反应性。此外，松鼠猴中 FEBP51 的过度表达可能是该物种黄体酮抵抗的一个原因。
FKBP51 and FKBP52 are large molecular weight FK506-binding immunophilins that have diverse biochemical functions. Best studied is the role that they play as components of steroid hormone receptors. Differential display and gene array screens have identified FKBP51 as a progestin-inducible gene. Here we demonstrate progestin enhancement of FKBP51 mRNA and protein in T-47D cells. FKBP51 mRNA and protein levels were increased 3-fold by 20 nm R5020. Induction of FKBP51 mRNA was unaffected by 1 mug/ml cycloheximide but was blocked by the progestin receptor (PR) antagonist RU486 (1 muM). Reporter plasmids containing 3.4 kb and 427 bp of 5'-flanking sequences of the human FKBP51 protein gene (FKBP5) exhibited regulation by progestin in T-47D cells. A construct containing 19 bp of upstream sequence demonstrated diminished basal activity and no stimulation by R5020. To test whether elevated FKBP51 affects progestin responsiveness, HepG2 cells were transfected with human FEBP51, PR, and mouse mammary tumor virus-luciferase plasmids, and treated with R5020 (0.03-10 nm). Expression of FKBP51 increased the EC50 for PR transactivation by 3.2-fold. Expression of FKBP51 from squirrel monkey, a New World primate with naturally occurring progestin resistance, increased the EC50 more dramatically (11.7-fold vs. control). Expression of FKBP51 bearing a double-point mutation in the tetratricopeptide repeat domain had no effect on PR transactivation. These results suggest that increased expression of FKBP51 by progestin may attenuate progestin responsiveness in hormone-conditioned cells. Furthermore, overexpression of FEBP51 in the squirrel monkey may be a contributing cause of progesterone resistance in this species.